// 云函数入口文件
const cloud = require('wx-server-sdk')

cloud.init()

// 云函数入口函数
exports.main = async (event, context) => {
  const wxContext = cloud.getWXContext()

 return await cloud.database().collection("student").doc(event._id).update({
    data: {
      'student_obj.openid': wxContext.OPENID
    }
  })
}